the man has been on the national stage for many years. this is mitt's first time on this kind of a stage. >> reporter: paul ryan, the vice presidential nominee, who is preparing for his own debate, again avoided giving details of the romney tax plan, even when pressed. >> you haven't given me the math. >> i don't have the -- it would take me too long to go through all of the math. >> reporter: the president is in nevada tonight for what insiders call three days of debate camp at a resort outside of las vegas. they too are trying to lower expectations and believe accounts that the romney campaign is convinced debates are about moments. >> the idea that i'm anti-immigrant is repulsive. >> reporter: and romney will come armed with several one-liners. >> clearly they've been practicing these zingers and lines for months, so i'm sure they'll have a bunch of clever line, but that's ultimately not what the american people are looking for. >> reporter: the president is being coached to be crisper, to shorten his answers, and a former democratic c